I'm likely the furthest thing away from a Hulk fanboy on this forum, and the level of power this Hulk would have backed by the Power Gem fighting in an enclosed area is staggering.
Going by recent portrayals of the Gem, it amped Parker Robbins from an average human to being able to physically dominate Red Hulk. If it amps Banner to the same degree (no reason why it wouldn't as the Gems are effectively used by will and Hulk's will is pretty strong and I'd wager he'd tap into the PG gem at least as well as Robbins if not better), Hulk's alpha strike is going to be ridiculous.